Handheld diabetes management device with bolus calculator

ABSTRACT

According to some embodiments of the present disclosure, a device and method for determining an allowable amount of blood glucose (bG) of a patient is disclosed. The method further includes receiving a current bG measurement, determining a target bG value, and determining a correction delta bG value based on one or more advice history records. The method includes determining a correction meal rise value and determining a maximum allowed bG value based on the target bG value, the correction delta bG value, and the correction meal rise value. The method includes setting the allowable amount of bG value equal to the maximum allowed bG value when the current bG measurement is greater than the target bG value and determining the allowable amount of bG value using the target bG value and the correction delta bG value when the current bG measurement is less than the target bG value.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation-in-part of U.S. Ser. No. 12/976,507filed Dec. 22, 2010. The disclosure of the above application isincorporated herein by reference.

FIELD

This disclosure relates to diabetes care medical devices used fordiagnostics and therapy, and more particularly to a diabetes managementdevice incorporating a bolus calculator that determines a maximumallowed blood glucose level of a patient to compare to a current bloodglucose measurement.

BACKGROUND

The statements in this section merely provide background informationrelated to the present disclosure and may not constitute prior art.

Diabetes mellitus, often referred to as diabetes, is a chronic conditionin which a person has elevated blood glucose levels that result fromdefects in the body's ability to produce and/or use insulin. There arethree main types of diabetes. Type 1 diabetes usually strikes childrenand young adults, and may be autoimmune, genetic, and/or environmental.Type 2 diabetes accounts for 90-95% of diabetes cases and is linked toobesity and physical inactivity. Gestational diabetes is a form ofglucose intolerance diagnosed during pregnancy and usually resolvesspontaneously after delivery.

In 2009, according to the World Health Organization, at least 220million people worldwide suffer from diabetes. In 2005, an estimated 1.1million people died from diabetes. Its incidence is increasing rapidly,and it is estimated that between 2005 and 2030, the number of deathsfrom diabetes will double. In the United States, nearly 24 millionAmericans have diabetes with an estimated 25 percent of seniors age 60and older being affected. The Centers for Disease Control and Preventionforecast that 1 in 3 Americans born after 2000 will develop diabetesduring their lifetime. The National Diabetes Information Clearinghouseestimates that diabetes costs $132 billion in the United States aloneevery year. Without treatment, diabetes can lead to severe complicationssuch as heart disease, stroke, blindness, kidney failure, amputations,and death related to pneumonia and flu.

Management of diabetes is complex as the level of blood glucose enteringthe bloodstream is dynamic. The variation of insulin that controls thetransport of glucose out of the bloodstream also complicates diabetesmanagement. Blood glucose levels are sensitive to diet and exercise, butalso can be affected by sleep, stress, smoking, travel, illness, menses,and other psychological and lifestyle factors unique to individualpatients. The dynamic nature of blood glucose and insulin, and all otherfactors affecting blood glucose, often require a person with diabetes tounderstand ongoing patterns and forecast blood glucose levels (or atleast understand the actions that raise or lower glucose in the body).Therefore, therapy in the form of insulin or oral medications, or both,can be timed to maintain blood glucose levels in an appropriate range.

Management of diabetes is often highly intrusive because of the need toconsistently obtain reliable diagnostic information, follow prescribedtherapy, and manage lifestyle on a daily basis. Daily diagnosticinformation, such as blood glucose, is typically obtained from acapillary blood sample with a lancing device and is then measured with ahandheld blood glucose meter. Interstitial glucose levels may beobtained from a continuous glucose sensor worn on the body. Prescribedtherapies may include insulin, oral medications, or both. Insulin can bedelivered with a syringe, an insulin pen, an ambulatory infusion pump,or a combination of such devices. With insulin therapy, calculating theamount of insulin to be injected can require determining mealcomposition of carbohydrates, fat and proteins along with effects ofexercise or other physiologic states. The management of lifestylefactors such as body weight, diet, and exercise can significantlyinfluence the type and effectiveness of a therapy.

Management of diabetes involves large amounts of diagnostic data andprescriptive data that are acquired from medical devices, personalhealthcare devices, patient recorded information, healthcareprofessional biomarker data, prescribed medications and recordedinformation. Medical devices including self-monitoring bG meters,continuous glucose monitors, ambulatory insulin infusion pumps, diabetesanalysis software, and diabetes device configuration software each ofwhich generates and/or manages large amounts of diagnostic andprescriptive data. Personal healthcare devices include weight scales,pedometers and blood pressure cuffs. Patient recorded informationincludes information relating to meals, exercise and lifestyle as wellas prescription and non-prescription medications. Healthcareprofessional biomarker data includes HbA1C, fasting glucose,cholesterol, triglycerides and glucose tolerance test results.Healthcare professional recorded information includes therapy and otherinformation relating to the patient's treatment.

There is a need for a patient device to aggregate, manipulate, manage,present, and communicate diagnostic data and prescriptive data frommedical devices, personal healthcare devices, patient recordedinformation, biomarker information and recorded information in anefficient manner to improve the care and health of a person withdiabetes, so the person with diabetes can lead a full life and reducethe risk of complications from diabetes.

Additionally, there is a need for a diabetes management device that isable to provide an even more accurate bolus recommendation to the userbased on various user inputs that take into account recent activitiesand events which may have an effect on the bG level of a patient to thusenhance the accuracy, convenience and/or efficiency of the device ingenerating a recommended bolus or a suggested carbohydrate amount forthe user.

SUMMARY

According to some embodiments of the present disclosure, acomputer-implemented method for determining an allowable amount of bloodglucose (bG) of a patient is disclosed. The allowable amount of bloodglucose is used to calculate a bolus recommendation for a patient. Themethod includes maintaining, at one or more processors, a plurality ofactive advice history records, each of the plurality of active advicehistory records having been generated during a predetermined time periodrelative to a current time, and each of the plurality of active advicehistory records identifying data relating to one or more bG influencingevents and including a time corresponding to the one or more bGinfluencing events. The method further includes receiving a current bGmeasurement corresponding to the patient, the current bG measurementindicating a current bG level of the patient. The method also includesdetermining a target bG value for the patient, the target bG valuecorresponding to a desired bG level for the patient. The method alsoincludes determining a correction delta bG value based on one or morerecords of the plurality of active advice history records, thecorrection delta bG value being indicative of an aggregated bG loweringeffect of the events defined in the one or more active advice historyrecords on a bG value of the patient. The method also includesdetermining a correction meal rise value based on a specific activeadvice history record of the plurality of active advice history records,the correction meal rise value being indicative of an amount the bGlevel of the patient can increase with respect to the target bG valuewithout requiring a correction bolus. The method further includesdetermining a maximum allowed bG value based on the target bG value, thecorrection delta bG value, and the correction meal rise value. Themethod further includes comparing the current bG measurement to thetarget bG value and setting the allowable amount of bG value equal tothe maximum allowed bG value when the current bG measurement is greaterthan the target bG value. The method also includes setting the allowableamount of bG value using the target bG value and the correction delta bGvalue and excluding the correction meal rise value when the current bGmeasurement is less than the target bG value. The method furtherincludes storing the allowable amount of bG value.

According to some embodiments of the present disclosure, when thecurrent bG measurement is less than the target bG value, the allowableamount of bG value is set equal to the sum of the target bG value andthe correction delta bG value.

In some embodiments determining the correction delta bG value furtherincludes, for each active advice history record of the plurality ofactive advice history records: analyzing the active advice historyrecord to determine a bG lowering effect associated with the activeadvice history record and aggregating the bG lowering effect associatedwith previous bG lowering effects corresponding to previously analyzedactive advice history records. The correction delta bG value isdetermined based on the aggregation of the bG lowering effect of all ofthe plurality of active advice history records.

In some embodiments determining the correction delta bG value furtherincludes, for each active advice history record of the plurality ofactive advice history records: after aggregating the bG lowering effectassociated with the previous bG lowering effects corresponding to thepreviously analyzed active history records, determining whether theaggregated bG lowering effect is less than zero, and when the aggregatedbG lowering effect is less than zero, setting the aggregated bG loweringeffect equal to zero. The correction delta bG value is determined basedon the aggregation of the bG lowering effect of all of the plurality ofactive advice history records and the active advice history records areanalyzed sequentially beginning with an oldest active advice historyrecord.

In some embodiments analyzing the active advice history record furtherincludes determining whether a bG measurement defined in the activeadvice history record is below a bG threshold. When the bG measurementdefined in the active history record is less than the bG threshold, thebG lowering effect associated with the active advice history record isdetermined based on a carbohydrate amount defined in the active advicehistory record. When the bG measurement defined in the active historyrecord is greater than the bG threshold, the bG lowering effectassociated with the active advice history record is determined based onan insulin amount defined in the active advice history record.

According to some embodiments of the present disclosure, analyzing theactive advice history record further includes determining an amount oftime that that has lapsed since the active advice history record hasbeen generated and comparing the amount of time to an offset timeassociated with the active advice history record, the offset timeindicating a first duration during which the events defined in theactive advice history record have a full effect on the bG level of thepatient. When the amount of time is greater than the offset time, the bGlowering effect associated with the active advice history record isdetermined based on:

$\frac{WorkingDeltabG}{{Acting\_ Time} - {Offset\_ Time}} \times \left( {{Acting\_ Time} - {Time}} \right)$where WorkingDeltabG is the bG lowering effect associated with theactive advice history record, Acting_Time is a second duration duringwhich the events defined in the active advice history records effect thebG level of a patient, Offset_Time is the offset time, and Time is theamount of time.

According to some embodiments of the present disclosure, determining thecorrection meal rise value includes ensuring the events defined in thespecific active advice history record include a bolus being associatedwith a carbohydrate intake event where the carbohydrate intake isgreater than a predetermined threshold and further include an indicationthat insulin was administered to the patient and correspond to a timethat is temporally closer to a current time than other active advicehistory records in the plurality of active advice history recordsdefining events that include a meal bolus and a confirmation of insulin.

According to some embodiments of the present disclosure, determining thecorrection meal rise value further includes determining an amount oftime that has lapsed since the time corresponding to the specific activeadvice history record and comparing the amount of time to an offset timeassociated with the specific active advice history record. When theamount of time is less than the offset time, the correction meal risevalue is set equal to a full meal rise value defined in the specificactive advice history record. When the amount of time is greater thanthe offset time, the correction meal rise value is set equal to anadjusted meal rise value based on the amount of time and the full mealrise value.

In some embodiments of the present disclosure the adjusted meal risevalue is determined according to:

$\frac{Meal\_ Rise}{{Acting\_ Time} - {Offset\_ Time}} \times \left( {{Acting\_ Time} - {Time}} \right)$where Meal_Rise is the full meal rise value associated with the specificactive advice history record, Offset_Time is a first duration duringwhich the events defined in the specific active advice history recordhave a full effect on the bG level of the patient, Acting_Time is asecond duration during which the events defined in the specific activeadvice history records effect the bG level of a patient, and Time is theamount of time.

According to some embodiments of the present disclosure, a method fordetermining a correction meal rise value is disclosed. The correctionmeal rise value is indicative of an amount the bG level of the patientcan increase with respect to a target bG value without requiring acorrection bolus. The method includes maintaining a plurality of activeadvice history records, each of the plurality of active advice historyrecords having been generated during a predetermined time periodrelative to a current time, and each of the plurality of active advicehistory records identifying data relating to a bG influencing event andincluding a time corresponding to the bG influencing event. The methodfurther includes identifying, at one or more processors, a specificactive advice history record of the plurality of active advice historyrecords, wherein the events defined in the specific active advicehistory record include a bolus being associated with a carbohydrateintake event where the carbohydrate intake is greater than apredetermined threshold and further including an indication that insulinwas administered to the patient in response to the bolus and correspondto a time that is more recent to a current time than other active advicehistory records in the plurality of active advice history recordsdefining events that include a meal bolus and a confirmation of insulin.The method also includes determining an amount of time that has lapsedsince the time corresponding to the specific active advice historyrecord, comparing the amount of time to a predetermined time threshold,and setting the correction meal rise value equal to a full meal risevalue as defined in the specific active advice history record when theamount of time is less than the predetermined time threshold. The methodalso includes setting the correction meal rise value equal to anadjusted meal rise value based on the amount of time and the full mealrise value when the amount of time is greater than the predeterminedtime threshold.

In some embodiments of the present disclosure, the adjusted meal risevalue is determined according to a predetermined linear function.

In some embodiments of the present disclosure, the adjusted meal risevalue is determined according to:

$\frac{Meal\_ Rise}{{Acting\_ Time} - {Offset\_ Time}} \times \left( {{Acting\_ Time} - {Time}} \right)$where Meal_Rise is the full meal rise value associated with the specificactive advice history record, Offset_Time is a first duration duringwhich the events defined in the specific active advice history recordhave a full effect on the bG level of the patient, Acting_Time is asecond duration during which the events defined in the specific activeadvice history records effect the bG level of a patient, and Time is theamount of time.

According to some embodiments of the present disclosure a diabetesmanagement device configured to determine an allowable amount of bloodglucose (bG) of a patient is disclosed. The allowable amount of bloodglucose is used to calculate a bolus recommendation for a patient. Thedevice includes an advice history records database that stores aplurality of active advice history records, each of the plurality ofactive advice history records having been generated during apredetermined time period relative to a current time, and each of theplurality of active advice history records identifying data relating toone or more bG influencing events and including a time corresponding tothe one or more bG influencing events. The device further includes acomputer-readable medium storing computer-readable instructions and oneor more processors configured to execute the computer-readableinstructions. The computer-readable instructions, when executed by theone or more processors, cause the one or more processors to receive acurrent bG measurement corresponding to the patient, the current bGmeasurement indicating a current bG level of the patient. The computerreadable instructions further cause the one or more processors todetermine a target bG value for the patient, the target bG valuecorresponding to a desired bG level for the patient. The computerreadable instructions further cause the one or more processors todetermine a correction delta bG value based on one or more records ofthe plurality of active advice history records, the correction delta bGvalue being indicative of an aggregated bG lowering effect of the eventsdefined in the one or more active advice history records on a bG valueof the patient. The computer readable instructions also cause the one ormore processors to determine a correction meal rise value based on aspecific active advice history record of the plurality of active advicehistory records, the correction meal rise value being indicative of anamount the bG level of the patient can increase with respect to thetarget bG value without requiring a correction bolus. The computerreadable instructions further cause the one or more processors todetermine, a maximum allowed bG value based on the target bG value, thecorrection delta bG value, and the correction meal rise value and tocompare the current bG measurement to the target bG value. The computerreadable instructions further cause the one or more processors to setthe allowable amount of bG value equal to the maximum allowed bG valuewhen the current bG measurement is greater than the target bG value. Thecomputer readable instructions further cause the one or more processorsto determine the allowable amount of bG value using the target bG valueand the correction delta bG value and excluding the correction meal risevalue when the current bG measurement is less than the target bG value.The computer readable instructions further cause the one or moreprocessors to store the allowable amount of bG value.

In some embodiments of the present disclosure, the computer readableinstructions, when executed by the one or more processors, cause the oneor more processors to set the allowable amount of bG value equal to thesum of the target bG value and the correction delta bG value when thecurrent bG measurement is less than the target bG value.

In some embodiments of the present disclosure, the computer readableinstructions, when executed by the one or more processors, further causethe one or more processors to, for each active advice history record ofthe plurality of active advice history records, analyze the activeadvice history record to determine a bG lowering effect associated withthe active advice history record and aggregate the bG lowering effectassociated with previous bG lowering effects corresponding to previouslyanalyzed active advice history records. The correction delta bG value isdetermined based on the aggregation of the bG lowering effect of all ofthe plurality of active advice history records and the active advicehistory records are analyzed sequentially beginning with an oldestactive advice history record.

In some embodiments of the present disclosure, the computer readableinstructions, when executed by the one or more processors, further causethe one or more processors to, for each active advice history record ofthe plurality of active advice history records: determine whether theaggregated bG lowering effect is less than zero after aggregating the bGlowering effect associated with the previous bG lowering effectscorresponding to the previously analyzed active history records, and toset the aggregated bG lowering effect equal to zero when the aggregatedbG lowering effect is less than zero.

In some embodiments of the present disclosure the computer readableinstructions, when executed by the one or more processors, further causethe one or more processors to determine whether a bG measurement definedin the active advice history record is below a bG threshold, determinethe bG lowering effect associated with the active advice history recordbased on a carbohydrate amount defined in the active advice historyrecord when the bG measurement defined in the active history record isless than the bG threshold, and determine the bG lowering effectassociated with the active advice history record based on an insulinamount defined in the active advice history record when the bGmeasurement defined in the active history record is greater than the bGthreshold.

In some embodiments of the present disclosure the computer readableinstructions, when executed by the one or more processors, further causethe one or more processors to determine an amount of time that that haslapsed since the active advice history record has been generated andcompare the amount of time to an offset time associated with the activeadvice history record, the offset time indicating a first durationduring which the events in the active advice history record have a fulleffect on the bG level of the patient. When the amount of time isgreater than the offset time, adjust the bG lowering effect associatedwith the active advice history record based on:

$\frac{WorkingDeltabG}{{Acting\_ Time} - {Offset\_ Time}} \times \left( {{Acting\_ Time} - {Time}} \right)$where WorkingDeltabG is the bG lowering effect associated with theactive advice history record, Acting_Time is a second duration duringwhich the events defined in the active advice history records effect thebG level of a patient, Offset_Time is the offset time, and Time is theamount of time.

According to some embodiments of the present disclosure, determining thecorrection meal rise value further includes ensuring events defined inthe specific active advice history record include a bolus beingassociated with a carbohydrate intake event where the carbohydrateintake is greater than a predetermined threshold and further include anindication that insulin was administered to the patient and correspondto a time that is more recent to a current time than other active advicehistory records in the plurality of active advice history recordsdefining events that include a meal bolus and a confirmation of insulin.

In some embodiments of the present disclosure the computer readableinstructions, when executed by the one or more processors, further causethe one or more processors to determine an amount of time that haslapsed since the time corresponding to the specific active advicehistory record, compare the amount of time to an offset time associatedwith the specific active advice history record, and set the correctionmeal rise value equal to a full meal rise value defined in the specificactive advice history record when the amount of time is less than theoffset time. When the amount of time is greater than the offset time,set the correction meal rise value equal to:

$\frac{Meal\_ Rise}{{Acting\_ Time} - {Offset\_ Time}} \times \left( {{Acting\_ Time} - {Time}} \right)$where Meal_Rise is the full meal rise value associated with the specificactive advice history record, Offset_Time is a first duration duringwhich the events defined in the specific active advice history recordhave a full effect on the bG level of the patient, Acting_Time is asecond duration during which the events defined in the specific activeadvice history records effect the bG level of a patient, and Time is theamount of time.

Further areas of applicability will become apparent from the descriptionprovided herein. It should be understood that the description andspecific examples are intended for purposes of illustration only and arenot intended to limit the scope of the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The following figures are selected embodiments of the diabetes managerwith enhanced data capability and related system embodiments andinformation.

FIG. 1 is a perspective view of one embodiment of a handheld diabetes bGmanagement device in accordance with the present disclosure;

FIG. 2 is a high level block diagram of various components andsubsystems that may be incorporated in the device shown in FIG. 1;

FIG. 3A is an exemplary flowchart illustrating a preliminaryconfiguration procedure for configuring the device shown in FIG. 1;

FIG. 3B is a drawing illustrating an example screen for enabling a userto program in various health events to be considered by the device whenproviding bolus recommendations;

FIG. 3C is an illustration showing how the display of the device maydisplay the various programmed health event options after same areprogrammed into the device;

FIG. 3D is a drawing of an exemplary layout that may be presented on thedisplay of the device for allowing the user to enter the percentageadjustment to be made to the health event;

FIG. 3E is an illustration showing how the display of the device maydisplay a message to the user if the user has selected more than onehealth event, and allows the user to enter a custom health adjustmentpercentage to be applied to a bolus calculation;

FIG. 3F is a drawing showing an exemplary layout of how various items ofinformation may be presented to the user on the display of the device;

FIGS. 4A and 4B represent an exemplary flowchart illustrating operationsthat can be performed in computing a total bolus using user definedhealth adjustment percentages by which the computed meal bolus andcomputed correction bolus can be modified (by the user) beforecalculating a recommended total bolus;

FIG. 5 is an exemplary flowchart illustrating operations that can beperformed by the device of FIG. 1 in calculating a carbohydratesuggestion for the user;

FIG. 6 is a flowchart illustrating exemplary operation performed by thedevice of FIG. 1 in computing the recommended meal bolus with a userprogrammed health adjustment applied thereto;

FIG. 7 is a flowchart illustrating exemplary operations that can beperformed in computing a recommended correction bolus with a healthadjustment percentage set by the user;

FIG. 8 is a flowchart illustrating exemplary operations that can beperformed by the device of FIG. 1 in computing a currently allowed bGvalue;

FIG. 9 is a flowchart illustrating exemplary operations that can beperformed by the device of FIG. 1 in computing a correction delta bGvalue;

FIG. 10 is a flowchart illustrating exemplary operations that can beperformed by the device of FIG. 1 in computing a correction meal risevalue;

FIGS. 11A and 11B are flowcharts illustrating exemplary operations thatcan be performed by the device of FIG. 1 in computing a working delta bGvalue based on an insulin history of the patient;

FIG. 12 is a flowchart illustrating exemplary operations that can beperformed by the device of FIG. 1 in computing a working delta bG valuebased on a carbohydrate history of the patient; and

FIGS. 13A and 13B are drawings illustrating an example of a lag timebeing incorporated to an action shape.

DETAILED DESCRIPTION

The following description is merely exemplary in nature and is notintended to limit the present disclosure, application, or uses.

Referring to FIG. 1, there is shown a high level drawing of oneembodiment of a handheld, diabetes management device 10 that may be usedin measuring the blood glucose (bG) of a patient and implementing abolus calculation or carbohydrate suggestion. Typically the device 10includes a housing 12 that may contain user unit control switches 14(e.g., ON/OFF), a touchscreen display 16, and a port 18 into which a bGtest strip 20 may be inserted. The display 16 may display userselectable options for allowing the user to access a software drivenmenu 16 a of various selections, a selection 16 b for allowing the userto enter bolus information, a selection 16 c for enabling the user toenter carbohydrate information for snacks or meals, and a selection 16 dfor allowing the user to enter information pertaining to health events(e.g., meals, exercise, periods of stress, periodic physiological eventssuch as a menstrual cycle, etc.) that may affect the user's bGmeasurement being read by the device 10. Although the display 16 will bedescribed herein as a touchscreen display, it will be appreciated thatany other suitable form of display may be incorporated (e.g., LED,etc.). If a touchscreen display is not used, the user control switches14 may need to include specific buttons or controls by which the user isable to select various options and input markers needed to carry out thebolus calculation or carbohydrate suggestion. It will be appreciatedthat the above is a high level description of the device 10, and inpractice the device may include additional controls, input ports, outputports, etc., as may be desired to even further enhance the utility ofthe device 10 or its use with other components and devices (e.g., laptopcomputers, infusion pumps, etc.). Accordingly, the above description ofthe device 10 should not be taken as limiting its construction orfeatures in any way.

Referring to FIG. 2, a high level block diagram of the device 10 isshown. The device 10 can include a rechargeable or non-rechargeablebattery 21 for powering the various electronic components of the device10. A processing subsystem 22 (e.g., a microprocessor based subsystem)is included that receives information from a bG analyzer 24. The bGanalyzer 24 is located adjacent the port 18 of the housing 12 to permitthe bG analyzer 24 to read the bG test strip 20. The bG analyzer 24 caninclude a code key 24 a that includes calibration information for the bGtest strip 20 being read. The processing subsystem 22 can also be incommunication with a database 26 that is used to store bG test valuesobtained from the bG analyzer 24 and other important health relatedinformation for the user. In particular, the database 26 can include asubsection 26 a for storing recommended bolus and carbohydrate advicehistory records (hereinafter “advice history records”) that are stillactive in their influence of current and future advice, and a section 26b for storing medication (insulin), health, carbohydrate and bG relatedvariables (e.g., insulin sensitivities of the user for various timesegments of the day) pertinent to the user. It will be appreciated thatthe database 26 will be formed by a non-volatile memory. Further, the bGrelated variables such as the insulin sensitivities of the user can bestored as global parameters and may not be in the advice historyrecords.

The processing subsystem 22 can also be in communication with thedisplay 16, the user control switches 14, and one or more interfaces 28for interfacing the device 10 to other external devices. The processingsubsystem 22 can also be in communication with a memory (such as a RAM)30 for storing various types of information (e.g., meal and bed times)that are input by the user, as well as any other information requiringtemporary or permanent storage. However, it will be appreciated that thedatabase 26 and the memory 30 could be implemented in a single memorydevice (e.g., RAM) if desired, as indicated in phantom in FIG. 2. Theprocessing subsystem 22 can be in communication with an alarm generationsubsystem 32 that is used to generate an alarm consisting of audiblesignals, tactile signals (e.g., a vibration signal) or possibly evenvisual signals such as illuminated lights (e.g., LEDs) on the device 10.The processing subsystem 22 can also receive inputs from a remotecontinuous glucose monitoring (“CGM”) device 34 secured to the user'sbody such that device 10 is continually updated with glucose informationfor the user. Finally the processing subsystem 22 can be incommunication with a remote insulin infusion pump 36 (herein referred toas an “insulin pump 36”) being worn by the user so that the device 10 isable to communicate bolus information to the insulin pump 36. By“remote” it is meant that the CGM device 34 and the insulin pump 36 areeach located outside of the device 10 but otherwise still incommunication with the device 10. It should be appreciated that thedevice 10 can communicate with the insulin pump 36 either through awired or wireless connection.

The device 10 can be used to implement a non-transitory machine readablecode, for example a bolus calculator software module 22 a (hereinreferred to as “bolus calculator 22 a”), that is run by the processingsubsystem 22. The bolus calculator 22 a can be formed as a single moduleor as a collection of independent modules that run concurrently on theprocessing subsystem 22. The processing subsystem 22, working inconnection with the bolus calculator 22 a, receives a wide variety ofuser inputs applied by the user through the touchscreen display 16 togenerate a recommended correction bolus, a recommended meal bolus, arecommended total bolus, or when appropriate a suggested carbohydrateamount. The suggested carbohydrate amount may be provided in response tothe detection by the device 10 of a hypoglycemic bG test value. Theoperations and capabilities of the device 10 will be explained in detailin the following paragraphs. The device 10 significantly enhances theconvenience and ease of use to the user through the implementation of aplurality of customizable inputs that enable the user to program thedevice 10 with unique health information pertinent to the user. Morespecifically, the device 10 allows the user to program the device 10with health information which even more completely enables the device 10to take into account unique health conditions affecting the user, aswell as regular occurring and non-regular occurring health events thatcould otherwise have an impact on the bolus and carbohydratecalculations made by the device 10.

In an example embodiment, the bolus calculator 22 a is configured togenerate advice history records which are indicative of the bolus andcarbohydrate calculations and bolus recommendations made by the device10. The bolus calculator 22 a may be further configured to include dataindicative of a patient's adherence or variance from the recommendationsin the advice history records. In some embodiments, an advice historyrecord can include a plurality of fields, including a time field thatdefines a time of the advice history record, a test flag field, a recordcontent field indicating one or more types of events defined in theadvice history record, and one or more fields defining valuescorresponding to the events indicated in the record content field.

In an exemplary embodiment, the advice history record includes a timefield. The time field denotes a time corresponding to the advice historyrecord. The time can include values indicating a year, a month, a day,an hour, and a minute of the advice history record. It should beappreciated that the time field can be divided into a plurality ofsubfields for each of the values. When a new advice history record isgenerated, the time at which the advice history record was generatedpopulates the time field.

In an exemplary embodiment, the test flag field indicates results of oneor more tests. The test field may include test flags corresponding tothe one or more tests. As should be appreciated, a test flag can be abit that is set to 1 if the result is true and 0 if the result is false.The test flags can include a HI test flag that indicates whether a bGconcentration value is outside of an upper range of values that can bedisplayed by the device 10. When the HI value is set to 1, the HI testflag indicates that a bG concentration value in above the range of bGconcentration values that can be displayed by the device 10. The testflags can further include a LO test flag. When the LO test flag is setto 1, the LO test flag indicates that the bG concentration value isbelow the range of values that can be displayed by the device 10. Thetest flags can also include a HYPO test flag. When the HYPO test flag isset to 1, the HYPO test flag indicates that the bG concentration valueof the patient corresponds to a hypoglycemic state or is below the lowerend of a target range. It is appreciated that the test field may includeadditional test flags.

As mentioned, the record content field indicates one or more types ofevents defined in the advice history record or that certain conditionsrelating to the events were met. The different types of events caninclude a blood glucose concentration, a carbohydrate amount associatedwith food intake of the patient, a health percentage value selected bythe user, an insulin amount was recommended to the patient, aconfirmation that insulin was administered to the patient, aconfirmation that a bolus recommendation was accepted by the patient, anindication that a correction bolus was administered, and an indicationthat a meal bolus was recommended to the patient. As should beappreciated, if one or more events are indicated in the record contentfield of the advice history record, the corresponding fields in theadvice history record are populated with values.

In an exemplary embodiment, the advice history record includes a bGconcentration field. The bG concentration field is populated with avalid value when the record content field indicates that a bGconcentration value has been associated with the advice history record.The bG concentration value indicates a bG concentration value from a bGmeasurement performed by the device 10 or was otherwise provided by thepatient. It should be appreciated that the bG concentration value can berepresented in mg/dL or mmol/L.

In an exemplary embodiment, the advice history record includes acarbohydrate amount field. The carbohydrate amount field is populatedwith a valid value when the record content field indicates that acarbohydrate amount value has been associated with the advice historyrecord. A carbohydrate amount value is an amount of carbohydrates that apatient consumed in a recent food intake. As will be discussed infurther detail below the carbohydrate amount value can be greater thanor less than a “snack size” threshold. When the carbohydrate amountvalue is greater than the “snack size” threshold the food intake isconsidered a meal as opposed to a snack. The carbohydrate value can beprovided by the patient via the user interface of the device 10 and canbe represented in grams.

In an exemplary embodiment, the advice history record includes a healthpercentage amount. The health percentage amount field is populated witha valid value when the record content field indicates that one or morehealth percentages have been associated with the advice history record.As discussed above, the user can enter different health events, e.g.,meals, exercise, periods of stress, and periodic physiological eventssuch as a menstrual cycle. The patient or another user can providepercentages representing an amount of effect that the health event hason increasing or decreasing the bG concentration (or insulin need) ofthe patient.

In an exemplary embodiment, the advice history record includes acorrection bolus field. The correction bolus field is populated with avalid value when the record content field indicates that a non-nullcorrection bolus amount has been associated with the advice historyrecord. The correction bolus amount indicates a bolus amount selected bya patient to either decrease or increase a bG concentration value. Anegative bolus amount corresponds to a scenario where the patient's bGconcentration is below a target bG value and a positive bolus amountcorresponds to a scenario where the patient's bG concentration is abovethe target bG value. It is noted that in some embodiments, thecorrection bolus field is populated when the user overrides a correctionbolus recommendation provided by the bolus calculator 22 a.

In an exemplary embodiment, the advice history record includes a mealbolus field. The meal bolus field is populated with a valid value whenthe record content field indicates that a non-null meal bolus amount hasbeen associated with the advice history record. The meal bolus amountindicates a bolus amount selected by a patient to either offset theeffects of a meal, e.g., carbohydrate intake. In some embodiments, themeal bolus field is populated when the user overrides a meal bolusrecommendation provided by the bolus calculator 22 a.

In an exemplary embodiment, the advice history record includes aconfirmed correction bolus field. The confirmed correction bolus fieldis populated with a valid value when the record content field indicatesthat a confirmed insulin amount and a non-null correction bolus amounthas been associated with the advice history record. The confirmedcorrection bolus amount indicates a bolus amount that was delivered tothe patient by an insulin pump 36 in response to a patient-savedcorrection bolus.

In an exemplary embodiment, the advice history record includes aconfirmed meal bolus field. The confirmed meal bolus field is populatedwith a valid value when the record content field indicates that aconfirmed insulin amount and a non-null meal bolus amount has beenassociated with the advice history record. The confirmed meal bolusamount indicates a bolus amount that was delivered to the patient by aninsulin pump 36 in response to a patient-saved meal bolus.

It should be appreciated that the advice history record may includevariations of the fields described above or alternative or additionalfields. The fields of the advice history record provided are providedfor example only and not intended to be limiting.

In some embodiments, the advice history record may include one or moredifferent parameter values relating to events defined in the advicehistory record. For example, the advice history record may include atarget value, a meal rise value, an offset time, and an acting timevalue. The target value is a target bG level of the patient. The targetvalue can be represented as a function of an upper and lower limit forthe patient's bG levels. The meal rise value is an amount by which thebG level of a patient may increase with respect to the target value as aresult of a carbohydrate intake. In some embodiments, the meal risevalue is a function of time and the administration of insulin, such thatthe meal rise remains constant for a first predetermined amount of timeafter the patient is administered insulin, i.e., offset time, and thendecreases linearly after the first predetermined amount of time. Thetotal amount of time that a dose of insulin has an effect on the bGlevels of a patient is the acting time. As will be discussed later, ifthe meal rise value as a result of the effect of a dose of insulin isgraphed, the result is referred to as an action shape. In someembodiments, the action shape is a trapezoid, such that the offset timedefines the shorter base and the acting time defines the longer base.Other parameters that may be included in the advice history record mayinclude a carb ratio value, an insulin sensitivity value, and a snacksize value. The parameter values may be provided by a user such as thepatient or a treating physician of the patient. The parameter values canbe uploaded or provided via the touch display 16 of the device 10. Theparameter values are utilized by the bolus calculator 22 a to determinebolus recommendations for the patient.

Referring to FIG. 3A, a flowchart 100 illustrates an exemplarypreliminary configuration procedure that the user can perform toconfigure the various inputs needed to tailor the device 10 to therequirements of the user. At operation 102 the user can define theinsulin type that she/he is using, as well as the “acting time” and“offset time” associated with the specified insulin. The user also setsa snack size at operation 104. Any carbohydrate amount greater than thesnack size that the user enters into the device 10 will be considered asa “meal” by the device 10 if the amount exceeds the user defined snacksize. A meal rise glucose amplitude (expressed in bG units) is alsodefined by the user at operation 105. At operation 106 the user candefine the various time blocks for a twenty four hour period. In oneexemplary implementation the user may define up to eight contiguous ornon-contiguous time blocks during a twenty four hour period. However, itwill be appreciated that a greater or lesser number of time blocks couldbe provided for. Since the user's insulin sensitivity will be assumed tovary over the course of the day, the user can set a different insulinsensitivity value for each time block, as indicated at operation 108. Atoperation 110 the user can set a carbohydrate ratio (“carb ratio”) foreach time block as well, as this ratio can be assumed to vary fordifferent users throughout the course of a day. At operation 112 theuser can set a bG target range for each time block, as this range isalso presumed to vary slightly over the course of a day. The bG targetrange is made up of an upper target bG value and a lower target bG valuewhich define the upper and lower bounds, respectively, of the bG targetrange. It will also be appreciated that the processing subsystem 22operates to consider an action shape of a previously taken correctionbolus, where the action shape is defined by a bG lowering potential ofthe previously taken correction bolus, as well as the offset time andthe acting time of the insulin associated with the previously takencorrection bolus. The action shape is considered by the processingsubsystem 22 when generating a new bolus recommendation, and will bediscussed in greater detail below.

At operation 114 the user labels each one of up to n different healthevents with a label using the touchscreen display 16 and assigns apercentage bG adjustment for each labeled health event. It is a valuablefeature of the device 10 that the user is able to program these variouspercentage adjustments for each of a plurality of user defined healthevents that the user knows in advance will affect her/his bG testvalues. For example, the user may program the device with different bGpercentage adjustment values for health events such as “exercise”,“illness”, “stress”, or even for recurring conditions such as amenstrual cycle. The precise percentages selected by the user for eachuser defined health event can be based on past history and experience ofthe user or based in part on the advice of a health care professionalwho is helping the user to manage her/his blood glucose levels. As oneexample, if the user knows from experience that an exercise eventperformed right after a meal will reduce a needed meal bolus by about20%, then the user may enter “−20” in a displayed field on the display16. The processing subsystem 22 will thereafter use this 20% reductionin calculating the meal bolus and the correction bolus when the exerciseevent has been selected. These features will be defined in greaterdetail in the following paragraphs.

Referring to FIGS. 3B-3F, illustrations are presented of how the variousforms of information can be displayed to the user on the display 16 ofthe device 10. FIG. 3B shows a screen 150 that presents multiple “HealthList Item” boxes that may be displayed in the display 16 when the userhas chosen to assign a specific health event to a record containing thebG test value that she/he has just obtained. FIG. 3C shows a screendisplay 150 a illustrating how this information can appear on thedisplay 16. The user can select one of the boxes 152 in FIG. 3C, whichwill mark the just-obtained bG test value with the user programmedspecific health event, and thus apply the user programmed percentageadjustment to the just-obtained bG test value. If the user selects twoor more health events for a single bG test value, then the device 10 candisplay a different screen that forces the user to select a “custom”health event percentage that will be applied to the just-obtained bGtest value. Such a screen layout 154 is shown in FIG. 3D. An actualexemplary screen display 156 is shown in FIG. 3E that corresponds to thescreen layout 154. The “Health” field 158 in FIG. 3E displays all thehealth events that the user has checked off in boxes 152 of screendisplay 150 a of FIG. 3C. In field 160 the user can enter and/or adjusta custom health percentage adjustment as indicated by the presence ofthe arrows 162 a and 162 b. Arrows 164 a and 164 b may also bedisplayed, which are used to enable the user to increase or decrease asuggested bolus. User control 166 enables the user to cancel the healthevent adjustment and control 168 enables the user to confirm theselection (i.e., apply) of the custom health percentage in field 160.FIG. 3F illustrates how various items of information (e.g., result bGtest value; carbohydrate information; health adjustment percentage;correction bolus; meal bolus; and total units of recommended bolus) canbe displayed to the user on the display 16.

Referring now to FIGS. 4A and 4B, a flowchart 200 is shown of exemplaryoperations that can be performed by the device 10 in determining a totalbolus recommendation for the user that takes into account theconfiguration programmed into the device 10 by the user. At operation202 an initialization operation is performed to set the record contentsof the processing subsystem 22 to “0”. At operation 204 the processingsubsystem 22 obtains the most current record stored in the database 26and checks at operation 206 to determine if it has an associated bG testvalue. If not, then at operation 208 the maximum allowed bG value iscomputed and displayed to the user. At operation 210 the processingsubsystem 22 determines the current time block. At operation 212 theprocessing subsystem 22 checks to determine if the user has selectedmore than one health event option and, if the user has selected morethan one option, a request is made on the display 16 for the user toenter a custom percentage value, as indicated at operation 214, thatwill be applied to subsequent meal bolus and correction boluscalculations. At operation 216 the processing subsystem 22 will computethe meal bolus and apply the selected health event adjustment defined bythe user (if any such adjustment has been selected by the user). Atoperation 218 the processing subsystem 22 will compute the total bolus.At operation 220 the processing subsystem 22 will update and store theoutput along with the record in the database 26 at operation 222.

Referring further to FIGS. 4A and 4B, if the check at operation 206reveals that there is a bG value associated with the most currentrecord, then a check is made at operation 224 to see if the “HI” testflag of the record is set, indicating a bG reading that is above adisplay limit of the device 10, and which therefore will not be used tocalculate a recommended correction bolus. If this check provides a “Yes”answer, then after the display of an appropriate warning at operation225 for a HI bG reading, operations 208-222 may be performed to obtainonly a recommendation for a meal bolus. If the check at operation 224produces a “No” answer, then a check is made to determine if the “LO” or“HYPO” test flags are set for the most current record (AdviceRecord_IN), as indicated at operation 226. This is an extra check toprevent the recommendation of a bolus in either a hypoglycemic conditionor with a bG reading below the display limit of the device 10. In theevent of a “Yes” answer, the routine of flowchart 200 ends (andflowchart 300 shown in FIG. 5 begins for calculating a carbohydratesuggestion). If the check at operation 226 produces a “No” answer, thenat operation 228 in FIG. 4B the processing subsystem 22 computes themaximum allowed bG value and displays it to the user on the display 16.

Continuing in FIG. 4B, at operation 230 the processing subsystem 22determines the current user defined time block. At operation 232 theprocessing subsystem 22 checks to determine if the user has selectedmore than one health event option and, if the user has selected morethan one option, a request is made on the display 16 for the user toenter a custom percentage value, as indicated at operation 234, thatwill be applied to the correction bolus calculation at operation 236. Atoperation 236 the processing subsystem 22 will compute the correctionbolus and apply the selected health event adjustment defined by the user(if any such adjustment has been selected by the user). Operations216-222 from FIG. 4A will then be applied. If the check at operation 232produces a “No” answer, the operation 236 will be performed using theuser set health event adjustment.

Turning to FIG. 5, a flowchart 300 is shown illustrating exemplaryoperations to show a carbohydrate suggestion can be calculated using thedevice 10 (this flow occurs based on the “Yes” path at operation 230 inFIG. 4A). At operation 302 an initialization procedure is performed toensure that any pre-existing data that may be present in the outputcontents of the processing subsystem 22 is cleared. The most currentrecord is then obtained at operation 304. At operation 306 a check ismade to determine if the HYPO test flag of the most current record isset, indicating a hypoglycemic condition for the current bG test valuebeing analyzed. If so, the processing subsystem 22 computes thecarbohydrate (“carb”) ratio at operation 308 in the traditional manner.At operation 310 the insulin sensitivity is calculated in thetraditional manner. At operation 312 the currently allowed bG iscomputed, which is described in greater detail below. At operation 314the current delta bG is computed by subtracting the currently allowed bGfrom the most current record bG concentration. So in effect, operation314 allows a previously taken correction bolus, which would operate tolower the user's bG, to be factored into the equation for determiningthe current delta bG. At operation 316 the current delta bG is convertedinto a carbohydrate suggestion using the insulin sensitivity and by thecarbohydrate ratio factors. At operation 318 the outputs of carbohydratesuggestion and current delta bG are stored.

Referring now to FIG. 6, a flowchart 400 is shown illustrating oneexemplary manner of computing a meal bolus with a health eventadjustment (this flow is called out at operation 216 of FIG. 4B). Atoperation 402 an initialization is performed to set the recommended mealbolus to a known value. At operation 404 a check is made to determine ifthe most current record retrieved by the processing subsystem 22 fromthe database 26 has a carbohydrate amount available for use in thefollowing calculations. If the answer is “Yes”, then at operation 406 acheck is made to ensure that the denominator of the carbohydrate ratiois not “0”. If it is not, then at operation 408 a bit will be set forthe output being created by the processing subsystem 22 to indicate arecommended meal bolus is associated with it. At operation 410 theworking meal bolus is calculated. At operation 412 a check is made if ahealth event adjustment percentage is set in the most current record. Ifso, then at operation 414 a working health percentage is set equal tothe health percentage contained in the most current record, and therecommended meal bolus is calculated using this working healthpercentage. For example, if the user has indicated “−20” in her/hispercentage adjustment for the associated health event, then operation414 uses this information to convert the “−20” to 80%, and the 80%figure is used to modify the working meal bolus to come up with therecommended meal bolus. Thus, in this example the recommended meal boluswould be reduced by 20%. At operation 418 the recommended meal bolusoutput just created by the processing subsystem 22 is saved in the logrecords portion 26 a of the database 26.

If the check at operation 412 indicates that no health percentageadjustment is indicated in the most current record, then the workinghealth adjustment percentage is set equal to zero at operation 416 andthen operations 414 and 418 are repeated. If in operation 404 it isunderstood that there is no carbohydrate amount from which a recommendedmeal bolus can be calculated, the recommended meal bolus of zero issimply saved at operation 418. If the denominator of the carbohydrateratio of the most current record is found to be “0” at operation 406,then the routine ends with an error condition.

Referring to FIG. 7, there is shown an exemplary flowchart 500 settingforth operations that can be performed in computing a correction bolus,taking into account a percentage health adjustment input by the user. Itwill be appreciated that the operations of flowchart 500 are called byoperation 236 in FIG. 4B.

At operation 502 the recommended correction bolus is initialized to aknown value. At operation 504 the working bG correction bolus iscalculated from the current delta bG (computed from the current bGvalue, the target bG, the most recent meal and/or previous correctionrecords), and the insulin sensitivity from the most current record. Atoperation 506 any health adjustment percentage present in the mostcurrent record is applied to the working health percentage. Again, ifthe user has specified “None” when selecting a health adjustmentpercentage for the bG test value associated with the most currentrecord, then the working health percentage will not be modified by anypercentage value, as shown at operation 510. At operation 508 therecommended correction bolus is obtained by modifying the working bGcorrection bolus by the health percentage adjustment. Thus, if the userhad set the health adjustment percentage for the bG test valueassociated with the most current record to “−25”, then the calculationat operation 512 would multiply the working bG correction bolus by 75%.The output with the newly calculated recommended correction bolus isthen saved to the database history logbook records 26 a at operation514.

In calculating the correction delta bG, an advantage of the device 10 isthat the working delta bG is allowed to be a negative value. This allowsa portion of any correction to be removed from the newly calculatedcorrection delta bG, such as if the user had previously taken somecarbohydrates to compensate for a LO or HYPO bG value, to be factoredinto the newly calculated correction delta bG. Another advantage is thatfor computing a carbohydrate suggestion for the user, therecommendations can be calculated to the currently allowed bG valuerather than to the center of the bG target range.

As was discussed with respect to FIG. 5, a currently allowed bG value iscomputed at operation 312. Similarly, a currently allowed bG value iscomputed at operation 504 of FIG. 7. In some embodiments, the boluscalculator 22 a computes the currently allowed bG value based on whetherthe current bG measurement of the patient is less than the target bGvalue of the patient. FIG. 8 illustrates an example method 600 forcomputing the currently allowed bG value. The currently allowed bG valueis indicative of a value that a patient's bG value may increase to at acurrent time without requiring correction bolus. As should beappreciated the method 600 may be executed by the processing subsystem22 of the device 10 and in particular, can be implemented as part of thebolus calculator 22 a. For purposes of explanation, the method 600 isexplained as being performed by the bolus calculator 22 a.

At operation 610, the bolus calculator 22 a computes a correction deltabG value. The correction delta bG value is indicative of an aggregatedbG lowering effect of the events defined in the one or more activeadvice history records of the patient. An example method for determiningthe correction delta bG value is described in further detail below andwith respect to FIG. 9.

At operation 612, the bolus calculator 22 a computes a target bG value.In some embodiments, the target bG value is determined as an average ofthe upper target bG value and the lower target bG value. The uppertarget bG value and the lower target bG value can be provided to thedevice 10 by the patient or another user such as the treating physician.Further, the upper target bG value and lower target bG value may bestored in the advice history records. Alternatively, the target bG valuecan be manually entered by a user.

At operation 614, the bolus calculator 22 a receives the current bGmeasurement value. As discussed above, the current bG measurement valuecan be determined when the patient provides a blood sample and the bloodsample is analyzed by the device 10.

At operation 616, the bolus calculator 22 a determines a correction mealrise value based on a specific advice history record of the plurality ofadvice history records. As will be discussed below, the specific advicehistory record that is used can include: i) an event corresponding tothe patient eating a meal that is greater than a snack size, ii) anevent corresponding to a meal bolus amount, and iii) an eventcorresponding to the patient or an insulin pump 36 verifying thatinsulin was actually administered to the patient. The correction mealrise value indicates an amount the bG level of the patient can increaseas a result of a meal eaten by the patient and with respect to thetarget bG value without requiring an additional correction bolus. Anexample technique for determining the correction meal rise value isdiscussed in greater detail below and with respect to FIG. 10.

At operation 618, the bolus calculator 22 a determines a maximum allowedbG value. The maximum allowed bG value indicates the maximum value forthe patient's bG measurement before recommending a correction bolus tothe patient. In some embodiments, the maximum bG value can be determinedby summing the target bG value, the correction delta bG value, and thecorrection meal rise value.

At operation 620, the bolus calculator 22 a compares the current bGmeasurement value with the target bG value. If the bolus calculator 22 adetermines that the current bG measurement value is greater than thetarget bG value, the bolus calculator sets the currently allowed bGvalue equal to the maximum allowed bG value, as shown at operation 622.If the bolus calculator 22 a determines that the current bG measurementvalue is less than the target value, the bolus calculator 22 a sets thecurrently allowed bG value equal to the sum of the target bG value andthe correction delta bG value, as shown at operation 624. At operation626, the bolus calculator 22 a stores the currently allowed bG value andmaximum allowed bG value.

It should be appreciated that the exemplary method 600 is provided forexample only. Variations of the method 600 are contemplated and arewithin the scope of the disclosure. Further, the ordering of theoperations are not intended to be limiting and different orderings arecontemplated and within the scope of the disclosure.

As was previously discussed, the bolus calculator 22 a determines acorrection delta bG value. The correction delta bG value indicates anaggregated bG lowering effect of the events defined in the advicehistory records. Put another way, the correction delta bG valueindicates the overall lowering effect of the insulin that is stillactive in the patient's body. In some embodiments, the bolus calculator22 a analyzes the active advice history records from the oldest activeadvice history record to the most recent active advice history record todetermine the aggregated bG lowering effect of the events definedtherein. FIG. 9 illustrates an exemplary method 700 for determining thecorrection delta bG value. For purposes of explanation, the method 700is described as being performed by the bolus calculator 22 a.

At operation 710, the bolus calculator 22 a retrieves the plurality ofactive advice history records. As previously described, the plurality ofactive advice history records are the advice history records definingevents that are still affecting the patient's bG levels. For example, ifan event defined in an advice history record is a correction bolus thatwas administered three hours prior to the current time and the activetime of the insulin dose was three or more hours, the advice historyrecord would be included in the plurality of active advice historyrecords. Conversely, an advice history record corresponding to 48 hoursprior to the current time, the advice history record would not beincluded in the plurality of active advice history records. At operation712, the bolus calculator 22 a selects the oldest advice history recordof the plurality of active advice history records.

At operation 714, the bolus calculator 22 a determines whether either ofthe HYPO test flag or the LO test flag in the selected advice historyrecord is set to 1. If so, the bolus calculator 22 a determines aworking delta bG value based on a carbohydrate intake of the patientdefined in the advice history record, as shown at operation 716. Ifneither the HYPO test flag or the LO test flag are set to 1 in theselected advice history record, the bolus calculator 22 a determines theworking delta bG value based on an insulin that was administered to thepatient at a time corresponding to the selected active history record,as shown at operation 718. The working delta bG value is the amount bywhich the patient's bG level is currently decreased or increased by as aresult of the events defined in the selected advice history record.

At operation 720, the bolus calculator 22 a determines the amount oftime that has lapsed since the selected advice history record wasgenerated. As discussed, the advice history record includes a timecorresponding to the advice history record. The bolus calculator 22 autilizes the time defined in the advice history record to determine theamount of time that has lapsed since the advice history record wasgenerated.

At operation 722, the bolus calculator 22 a determines whether theamount of time that has lapsed since the advice history record wasgenerated is greater than the offset time defined in the advice historyrecord. If the amount of time is less than the offset time, then thebolus calculator 22 a increments the correction delta bG value by thefull amount of the working delta bG value, as shown at operation 724. Ifthe amount of time is greater than the offset time, the bolus calculator22 a increments the correction delta bG value by the result of apredetermined formula, as shown at operation 726. For example, in someembodiments the correction delta bG value is incremented by the amount:

$\frac{WorkingDeltabG}{{Acting\_ Time} - {Offset\_ Time}} \times \left( {{Acting\_ Time} - {Time}} \right)$Where Acting_Time is the duration during which events defined in theselected advice history record effects the bG level of a patient,Offset_Time is the duration during which the full effect of eventsdefined in the selected advice history record apply, and Time is thedifference between the current time and the time when the advice historyrecord was generated. As should be appreciated, the differences in time,e.g., Acting_Time−Offset_Time and Acting_Time−Time may be represented inminutes or seconds. Furthermore, Acting_Time and Offset_Time may bedefined in the selected active history record.

At operation 728, the bolus calculator 22 a compares the running totalof the correction delta bG value to a predetermined threshold, e.g., 0.As should be appreciated, the bolus calculator 22 a aggregates the totaleffect of bG influencing events defined in the plurality of activeadvice history records to calculate the correction delta bG. At eachiteration, e.g., after analyzing another active advice history record,if the running total is less than 0, the bolus calculator 22 a sets therunning total for the correction delta bG to 0 at operation 730.Otherwise, the running total for the correction delta bG is not altered.

At operation 732, the bolus calculator 22 a determines whether there areany remaining active advice history records remaining in the pluralityof active advice history records left to analyze. If so, the boluscalculator 22 a obtains the next advice history record, as shown atoperation 734, and repeats the operations described above. Else, thebolus calculator 22 a stops the routine and stores the aggregatedcorrection delta bG value.

It is appreciated that the foregoing method 700 is provided for exampleonly and not intended to be limiting. Other techniques for determiningthe correction delta bG value are contemplated and are within the scopeof the disclosure.

As described above, the bolus calculator 22 a is configured to determinea correction meal rise value, which is indicative of an amount the bGlevel of the patient can increase with respect to the target bG valuewithout requiring a meal bolus. In some embodiments, the boluscalculator 22 a analyzes the active advice history records to select themost recent relevant active advice history record. Using the selectedactive advice history record, the bolus calculator 22 a determines theamount of time that has lapsed since the record was generated todetermine the correction meal rise value. FIG. 10 illustrates an examplemethod 800 for determining a correction meal rise value. For purposes ofexplanation, the method 800 is explained as being executed by the boluscalculator 22 a.

At operation 810, the bolus calculator 22 a obtains the plurality ofactive advice history records. As described previously, the plurality ofactive advice history records are the advice history records that weregenerated within an acting time. That is, the events defined in theadvice history record may be still influencing the bG measurements of apatient. At operation 812, the bolus calculator 22 a selects the mostrecent advice history record.

At operation 814, the bolus calculator 22 a analyzes the selected advicehistory record to determine whether the advice history record includes:i) an event corresponding to the patient eating a meal that is greaterthan a snack size, ii) an event corresponding to a meal bolus amount,and iii) an event corresponding to the patient or an insulin pump 36verifying that insulin was actually administered to the patient.

If one or more of the conditions are not met, the bolus calculator 22 aobtains the next most recent advice history record, as shown atoperation 816. If all of the above-identified conditions are met, thebolus calculator 22 a determines the time of the selected advice historyrecord, as shown at operation 818. It is noted that if the boluscalculator 22 a cannot identify a record meeting the above-statedcriteria, the method ends and the meal rise value is set equal to 0.

At operation 820, the bolus calculator 22 a determines the amount oftime that has lapsed since the selected advice history record wasgenerated. At operation 822, the bolus calculator 22 a determineswhether the amount of time that has lapsed is less than the offset timedefined in the selected advice history record. If the amount of time isless than the offset time, the correction meal rise value is set equalto the full amount of the meal rise value, as indicated in the actionshape defining meal rise values, as shown at operation 824. Asdiscussed, the values of the action shape may be entered by a user suchas the patient or a treating physician. If, however the amount of timeis greater than the offset time, the bolus calculator 22 a sets thecorrection meal rise value equal to an adjusted meal rise value, asshown at 826. In some embodiments, the bolus calculator 22 a sets thecorrection meal rise value equal to the result of a predeterminedformula, as shown at 826. For example, the adjusted meal rise value canbe set equal to the result of the following formula:

$\frac{Meal\_ Rise}{{Acting\_ Time} - {Offset\_ Time}} \times \left( {{Acting\_ Time} - {Time}} \right)$where Meal_Rise is the full meal rise value defined in the action shapecorresponding to the selected advice history record, Acting_Time is theduration during which the selected advice history record effect the bGlevel of a patient, Offset_Time is the duration during which the fulleffect of the events defined in the selected advice history recordapply, and Time is the amount of time since the selected advice historyrecord was generated. Acting_Time and Offset_Time may be defined in theselected active history record. At operation 828, the correction mealrise value is stored.

It is appreciated that the foregoing method 800 is provided for exampleonly and not intended to be limiting. Other techniques for determiningthe correction meal rise value are contemplated and are within the scopeof the disclosure.

As previously discussed with respect to FIG. 9, when the boluscalculator 22 a is determining the working correction delta bG value fora particular advice history record, the bolus calculator 22 a determineswhether the HYPO or LO test flag is set to true. If neither flag is set,the bolus calculator determines the working delta bG value based on theinsulin history of the patient. FIGS. 11A and 11B together illustrate anexample method 900 for determining the working delta bG value based onthe insulin history the patient.

At operation 910, the bolus calculator 22 a obtains the advice historyrecord for which the working correction delta bG value is beingcalculated. At operation 912, the bolus calculator 22 a determineswhether the events defined in the advice history record include aconfirmation that insulin was administered to the patient by an insulinpump 36. If so, a working correction bolus value is set equal to theconfirmed correction bolus value identified in the advice history recordand a working meal bolus value is set equal to the confirmed meal bolusvalue identified in the advice history record, as shown at operations914 and 916, respectively. If there was no confirmed insulin defined inthe advice history record, the bolus calculator 22 a sets the workingcorrection bolus value equal to the user selected correction bolus valueidentified in the advice history record and the working meal bolus valueequal to the user selected meal bolus value, as shown at operations 918and 920, respectively.

At operation 922, the bolus calculator 22 a determines whether thehealth percentage value defined in the advice history record is defined.If a health percentage value is defined, the working correction bolus isset equal to:

$\left( \frac{WorkingCorrectionBolus}{1 + {HealthPercentage}} \right)$where WorkingCorrectionBolus is the working correction bolus value asdetermined above and HealthPercentage is the health percentage valuedefined in the advice history record, as shown at operation 924. It isappreciated that the health percentage value can be a decimalrepresentation of the percentage. Further, at operation 926, the workingmeal correction bolus value is set equal to:

$\left( \frac{WorkingMealBolus}{1 + {HealthPercentage}} \right)$where WorkingMealBolus is the working correction bolus value determinedabove. It is appreciated that the health percentage value can be adecimal representation of the percentage. If at operation 922, a healthpercentage is not defined, the working correction bolus and the workingmeal bolus values are left unchanged.

At operation 928, the bolus calculator 22 a determines whether theworking correction bG value is equal to 0. If so, the bolus calculator22 a sets the working delta bG value equal to 0, as shown at operation929, and the process returns the working delta bG value.

If the working correction bG value is not equal to 0, the boluscalculator 22 a determines whether the sum of the working correctionbolus value and the working meal bolus value is less than 0, as shown atoperation 930. If so, the bolus calculator 22 a, as shown at operation932, calculates the working delta bG value according to:

${{Working\_ Delta}{\_ bG}{\_ value}} = {{- 1} \times {WorkingMealBolus} \times \left( \frac{InsulinSensitivitybG}{InsulinSensitivityInsulin} \right)}$where WorkingMealBolus is the working meal bolus value determined above,and InsulinSensitivitybG and InsulinSensitivityInsulin are predeterminedvalues provided by the patient or another user in the advice historyrecord. Once the working delta bG value is determined the method 900ends.

If, however, the sum of the working correction bolus value and theworking meal bolus value is not less than 0, the bolus calculator 22 adetermines whether the patient had accepted the bolus recommendationidentified in the advice history record, as shown at operation 934. Ifso, at operation 936 the bolus calculator 22 a determines the workingdelta bG value according to:Working_Delta_bG_value=bG_Concentration−Currently_Allowed_bGwhere bG_Concentration is the measured bG concentration value identifiedin the advice history record and the Currently_Allowed_bG is thecurrently allowed bG value in the advice history record, the calculationof which was described in greater detail above. If the advice historyrecord does not indicate that the bolus recommendation was accepted, atoperation 938 the bolus calculator 22 a determines the working delta bGvalue according to:

${{Working\_ Delta}{\_ bG}{\_ value}} = {{WorkingCorrectionBolus} \times \left( \frac{InsulinSensitivitybG}{InsulinSensitivityInsulin} \right)}$where WorkingCorrectionBolus is the working correction bolus value,described above, and InsulinSensitivitybG and InsulinSensitivityInsulinare predetermined values provided by the patient or another user in theadvice history record. Once the working delta bG value is determined,the working delta bG value is returned and the method 900 stopsexecuting.

It is appreciated that the foregoing method 900 is provided for exampleonly and not intended to be limiting. Other techniques for determiningthe working delta bG value are contemplated and are within the scope ofthe disclosure.

As previously discussed with respect to FIG. 9, when the boluscalculator 22 a is determining the working correction delta bG value fora particular advice history record, the bolus calculator 22 a determineswhether the HYPO or LO test flag is set to true. If one or both flagsare set, the bolus calculator 22 a determines the working delta bG valuebased on the carbohydrate history of the patient. FIG. 12 illustrates anexample method 1000 for determining the working delta bG value based onthe carbohydrate history the patient.

At operation 1010, the bolus calculator 22 a receives the advice historyrecord for which the working correction delta bG value is beingcalculated. At operation 1012, the bolus calculator 22 a determineswhether the LO test flag is set. If the LO test flag is not set, atoperation 1014 the bolus calculator 22 a determines whether the bolusrecommendation indicated in the advice history record was accepted. Ifthe bolus recommendation was accepted, at operation 1016 the boluscalculator 22 a determines the working delta bG value according to thefollowing:Working_Delta_bG_value=bG_Concentration−Currently_Allowed_bGwhere bG_Concentration is the measured bG concentration value identifiedin the advice history record and the Currently_Allowed_bG is thecurrently allowed bG value in the advice history record.

If the advice history record indicates that the LO test flag was true orthe bolus recommendation was not accepted, the bolus calculator 22 adetermines whether a carbohydrate amount value as associated with theadvice history record, as shown at operation 1018. If not, the workingdelta bG value is set equal to 0, as shown at operation 1020. If acarbohydrate value was associated with the advice history record, atoperation 1022 the bolus calculator 22 a calculates the working delta bGvalue according to:

${{Working\_ Delta}{\_ bG}{\_ value}} = {{- 1} \times {CarbAmount} \times \left( \frac{InsulinSensitibitybG}{InsulinSensitivityInsulin} \right) \times \left( \frac{CarbRatioInsulin}{CarbRatioCarbs} \right)}$where CarbAmount is the carbohydrate amount value associated with theadvice history record and InsulinSensitivitybG,InsulinSensitivityInsulin, CarbRatioInsulin and CarbRatioCarbs arepredetermined values provided by the patient or another user in theadvice history record. Once the working delta bG value is determined,the working delta bG value is returned and the method 1000 stopsexecuting.

It is appreciated that the foregoing method 1000 is provided for exampleonly and not intended to be limiting. Other techniques for determiningthe working delta bG value are contemplated and are within the scope ofthe disclosure.

In some embodiments, the patient can provide an indication to the boluscalculator 22 a that a dose of insulin will be administered in the nearfuture, e.g., in about 10 minutes. In these embodiments, the boluscalculator 22 a can adjust the offset time in the advice history recordto compensate for the lag time that will result from the lateradministered insulin. FIGS. 13A and 13B illustrate an example of lagtime being compensated for in such a situation. In FIG. 13A, an actionshape 1100 is illustrated. The action shape 1100 of FIG. 13A presumesthat the patient will administer insulin at the time of the bolusrecommendation. If, however, the patient provides an indication that theinsulin will be administered shortly thereafter, the bolus calculator 22a can adjust the offset time and acting time defined in the action shapeto account for the lag time between the bolus recommendation and whenthe insulin will be administered. FIG. 13B illustrates an example of theaction shape 1100 after the lag time is accounted for. As should beappreciated, the offset time and the acting time have both beenincreased by the lag time.

In some embodiments, the patient can turn a bolus advice feature on oroff. When the bolus advice feature is turned off, the bolus calculator22 a may be configured not to generate advice history records forvarious events. If, however, the patient decides to turn the bolusadvice feature on, the bolus calculator 22 a may require previous advicehistory records to perform the methods described above. Thus, in someembodiments, when the patient turns the bolus advice feature on, thebolus calculator 22 a creates a plurality of advice history records andback-fills the parameter values described above with the values providedby the user, e.g., the patient or the patient's physician. In theseembodiments, the various fields may be left empty as the particulardata, e.g., bG measurement values and meal histories, to fill the valuesmay not have been recorded. If, however, the data was maintained, thedata may be automatically back-filled into the advice history records aswell.

In some embodiments, the patient can provide instructions to the insulinpump 36 to deliver a bolus. The user has the option to manually deliverthe bolus. When the bolus is administered, the bolus calculator 22 aincludes the amount of bolus delivered to the patient. A situation mayarise however, where the patient is provided with a bolusrecommendation, including a recommended amount of insulin, but manuallydelivers a bolus amount that does not match the recommended amount ofinsulin. This may be because the patient was unable to enter the preciseamount using the user interface of the insulin pump 36 or because of apartial delivery error by the pump. Thus, in some embodiments, the boluscalculator 22 a is configured to compare the amount manually entered bythe patient as the bolus amount delivered to the bolus recommendationamount. If there is a discrepancy, the bolus calculator 22 a determineswhether the discrepancy was due to the patient being unable to enter theexact amount using the user interface of the insulin pump 36, e.g., ifthe amount entered is within a “step-size” of the bolus recommendation.If this is the case, the bolus calculator 22 a stores the recommendationaccepted as “TRUE” (for example in operation 934). If, however, theamount entered is much greater or much less than the bolusrecommendation, the bolus calculator 22 a stores the recommendationaccepted as “FALSE” and acts on the amount of insulin manually enteredby the patient.

What is claimed is:
 1. A computer-implemented method for determining anallowable amount of blood glucose (bG) of a patient, the allowableamount of blood glucose being used to calculate a bolus recommendationfor a patient, the method comprising: maintaining a plurality of activeadvice history records in a data store of a computing device, each ofthe plurality of active advice history records having been generatedduring a predetermined time period relative to a current time, and eachof the plurality of active advice history records identifying datarelating to one or more bG influencing events and including a timecorresponding to the one or more bG influencing events; measuring, by asensor of the computing device, a current bG measurement correspondingto the patient, the current bG measurement indicating a current bG levelof the patient; determining, by one or more processors of the computingdevice, a target bG value for the patient, the target bG valuecorresponding to a desired bG level for the patient; determining, at theone or more processors, a correction delta bG value based on one or morerecords of the plurality of active advice history records, thecorrection delta bG value being indicative of an aggregated bG loweringeffect of the events defined in the one or more active advice historyrecords on a bG value of the patient; determining, at the one or moreprocessors, a correction meal rise value based on a specific activeadvice history record of the plurality of active advice history records,the correction meal rise value being indicative of an amount the bGlevel of the patient can increase with respect to the target bG valuewithout requiring a correction bolus; determining, at the one or moreprocessors, a maximum allowed bG value based on the target bG value, thecorrection delta bG value, and the correction meal rise value;comparing, at the one or more processors, the current bG measurement tothe target bG value; setting, at the one or more processors, theallowable amount of bG value equal to the maximum allowed bG value whenthe current bG measurement is greater than the target bG value; setting,at the one or more processors, the allowable amount of bG value usingthe target bG value and the correction delta bG value and excluding thecorrection meal rise value when the current bG measurement is less thanthe target bG value; storing the allowable amount of bG value in thedata store of the computing device; calculating, at the one or moreprocessors, a recommendation for the patient using the allowable amountof bG value; and presenting the recommendation to the patient on adisplay of the computing device.
 2. The method of claim 1, wherein whenthe current bG measurement is less than the target bG value, theallowable amount of bG value is set equal to the sum of the target bGvalue and the correction delta bG value.
 3. The method of claim 1,wherein determining the correction delta bG value further comprises: foreach active advice history record of the plurality of active advicehistory records: analyzing the active advice history record to determinea bG lowering effect associated with the active advice history record;and aggregating the bG lowering effect associated with previous bGlowering effects corresponding to previously analyzed active advicehistory records, wherein the correction delta bG value is determinedbased on the aggregation of the bG lowering effect of all of theplurality of active advice history records.
 4. The method of claim 3,wherein determining the correction delta bG value further comprises: foreach active advice history record of the plurality of active advicehistory records: after aggregating the bG lowering effect associatedwith the previous bG lowering effects corresponding to the previouslyanalyzed active history records, determining whether the aggregated bGlowering effect is less than zero; and when the aggregated bG loweringeffect is less than zero, setting the aggregated bG lowering effectequal to zero, wherein the correction delta bG value is determined basedon the aggregation of the bG lowering effect of all of the plurality ofactive advice history records and the active advice history records areanalyzed sequentially beginning with an oldest active advice historyrecord.
 5. The method of claim 3, wherein analyzing the active advicehistory record further comprises: determining whether a bG measurementdefined in the active advice history record is below a bG threshold;when the bG measurement defined in the active history record is lessthan the bG threshold, determining the bG lowering effect associatedwith the active advice history record based on a carbohydrate amountdefined in the active advice history record; and when the bG measurementdefined in the active history record is greater than the bG threshold,determining the bG lowering effect associated with the active advicehistory record based on an insulin amount defined in the active advicehistory record.
 6. The method of claim 3, wherein analyzing the activeadvice history record further comprises: determining an amount of timethat that has lapsed since the active advice history record wasgenerated; comparing the amount of time to an offset time associatedwith the active advice history record, the offset time indicating afirst duration during which the events defined in the active advicehistory record have a full effect on the bG level of the patient; whenthe amount of time is greater than the offset time, adjusting the bGlowering effect associated with the active advice history record basedon:$\frac{WorkingDeltabG}{{Acting\_ Time} - {Offset\_ Time}} \times \left( {{Acting\_ Time} - {Time}} \right)$where WorkingDeltabG is the bG lowering effect associated with theactive advice history record, Acting_Time is a second duration duringwhich the events defined in the active advice history records effect thebG level of a patient, Offset_Time is the offset time, and Time is theamount of time.
 7. The method of claim 1, wherein determining thecorrection meal rise value comprises ensuring the events defined in thespecific active advice history record include a bolus being associatedwith a carbohydrate intake event where the carbohydrate intake isgreater than a predetermined threshold and further include an indicationthat insulin was administered to the patient and correspond to a timethat is temporally closer to a current time than other active advicehistory records in the plurality of active advice history recordsdefining events that include a meal bolus and a confirmation of insulin.8. The method of claim 1, wherein determining the correction meal risevalue further comprises: determining an amount of time that has lapsedsince the time corresponding to the specific active advice historyrecord; comparing the amount of time to a predetermined thresholdassociated with the specific active advice history record; when theamount of time is less than the predetermined threshold, setting thecorrection meal rise value equal to a full meal rise value defined inthe specific active advice history record; and when the amount of timeis greater than the predetermined threshold, setting the correction mealrise value equal to an adjusted meal rise value based on the amount oftime and the full meal rise value.
 9. The method of claim 8, wherein theadjusted meal rise value is determined according to:$\frac{Meal\_ Rise}{{Acting\_ Time} - {Offset\_ Time}} \times \left( {{Acting\_ Time} - {Time}} \right)$where Meal_Rise is the full meal rise value associated with the specificactive advice history record, Offset_Time is a first duration duringwhich the events defined in the specific active advice history recordhave a full effect on the bG level of the patient, Acting_Time is asecond duration during which the events defined in the specific activeadvice history records effect the bG level of a patient, and Time is theamount of time.
 10. A diabetes management device configured to determinean allowable amount of blood glucose (bG) of a patient, the allowableamount of blood glucose being used to calculate a bolus recommendationfor a patient, the device comprising: an advice history records databasethat stores a plurality of active advice history records, each of theplurality of active advice history records having been generated duringa predetermined time period relative to a current time, and each of theplurality of active advice history records identifying data relating toone or more bG influencing events and including a time corresponding tothe one or more bG influencing events; a computer-readable mediumstoring computer-readable instructions; one or more processorsconfigured to execute the computer-readable instructions, thecomputer-readable instructions, when executed by the one or moreprocessors, causing the one or more processors to: receive a current bGmeasurement corresponding to the patient, the current bG measurementindicating a current bG level of the patient; determine a target bGvalue for the patient, the target bG value corresponding to a desired bGlevel for the patient; determine a correction delta bG value based onone or more records of the plurality of active advice history records,the correction delta bG value being indicative of an aggregated bGlowering effect of the events defined in the one or more active advicehistory records on a bG value of the patient; determine a correctionmeal rise value based on a specific active advice history record of theplurality of active advice history records, the correction meal risevalue being indicative of an amount the bG level of the patient canincrease with respect to the target bG value without requiring acorrection bolus; determine, a maximum allowed bG value based on thetarget bG value, the correction delta bG value, and the correction mealrise value; compare the current bG measurement to the target bG value;set the allowable amount of bG value equal to the maximum allowed bGvalue when the current bG measurement is greater than the target bGvalue; determine the allowable amount of bG value using the target bGvalue and the correction delta bG value and excluding the correctionmeal rise value when the current bG measurement is less than the targetbG value; and store the allowable amount of bG value.
 11. The device ofclaim 10, wherein the computer readable instructions, when executed bythe one or more processors, cause the one or more processors to set theallowable amount of bG value equal to the sum of the target bG value andthe correction delta bG value when the current bG measurement is lessthan the target bG value.
 12. The device of claim 10, wherein thecomputer readable instructions, when executed by the one or moreprocessors, further cause the one or more processors to: for each activeadvice history record of the plurality of active advice history records:analyze the active advice history record to determine a bG loweringeffect associated with the active advice history record; and aggregatethe bG lowering effect associated with previous bG lowering effectscorresponding to previously analyzed active advice history records,wherein the correction delta bG value is determined based on theaggregation of the bG lowering effect of all of the plurality of activeadvice history records and the active advice history records areanalyzed sequentially beginning with an oldest active advice historyrecord.
 13. The device of claim 12, wherein the computer readableinstructions, when executed by the one or more processors, further causethe one or more processors to: for each active advice history record ofthe plurality of active advice history records: after aggregating the bGlowering effect associated with the previous bG lowering effectscorresponding to the previously analyzed active history records,determine whether the aggregated bG lowering effect is less than zero;and set the aggregated bG lowering effect equal to zero when theaggregated bG lowering effect is less than zero.
 14. The device of claim12, wherein the computer readable instructions, when executed by the oneor more processors, further cause the one or more processors to:determine whether a bG measurement defined in the active advice historyrecord is below a bG threshold; determine the bG lowering effectassociated with the active advice history record based on a carbohydrateamount defined in the active advice history record when the bGmeasurement defined in the active history record is less than the bGthreshold; and determine the bG lowering effect associated with theactive advice history record based on an insulin amount defined in theactive advice history record when the bG measurement defined in theactive history record is greater than the bG threshold.
 15. The deviceof claim 12, wherein the computer readable instructions, when executedby the one or more processors, further cause the one or more processorsto: determine an amount of time that that has lapsed since the activeadvice history record was generated; compare the amount of time to anoffset time associated with the active advice history record, the offsettime indicating a first duration during which the events in the activeadvice history record have a full effect on the bG level of the patient;when the amount of time is greater than the offset time, adjust the bGlowering effect associated with the active advice history record basedon:$\frac{WorkingDeltabG}{{Acting\_ Time} - {Offset\_ Time}} \times \left( {{Acting\_ Time} - {Time}} \right)$where WorkingDeltabG is the bG lowering effect associated with theactive advice history record, Acting_Time is a second duration duringwhich the events defined in the active advice history records effect thebG level of a patient, Offset_Time is the offset time, and Time is theamount of time.
 16. The device of claim 10 wherein determining thecorrection meal rise value further comprises ensuring the events definedin the specific active advice history record include a bolus beingassociated with a carbohydrate intake event where the carbohydrateintake is greater than a predetermined threshold and further include anindication that insulin was administered to the patient and correspondto a time that is more recent to a current time than other active advicehistory records in the plurality of active advice history recordsdefining events that include a meal bolus and a confirmation of insulin.17. The device of claim 10, wherein the computer readable instructions,when executed by the one or more processors, further cause the one ormore processors to: determine an amount of time that has lapsed sincethe time corresponding to the specific active advice history record;compare the amount of time to an offset time associated with thespecific active advice history record; set the correction meal risevalue equal to a full meal rise value defined in the specific activeadvice history record when the amount of time is less than the offsettime; and when the amount of time is greater than the offset time, setthe correction meal rise value equal to:$\frac{Meal\_ Rise}{{Acting\_ Time} - {Offset\_ Time}} \times \left( {{Acting\_ Time} - {Time}} \right)$where Meal_Rise is the full meal rise value associated with the specificactive advice history record, Offset_Time is a first duration duringwhich the events defined in the specific active advice history recordhave a full effect on the bG level of the patient, Acting_Time is asecond duration during which the events defined in the specific activeadvice history records effect the bG level of a patient, and Time is theamount of time.
 18. The device of claim 10 further comprises a bGanalyzer configured to receive a test strip and operates to determinethe current bG measurement from a sample of blood on the test strip. 19.The device of claim 10 wherein the computer readable instructions, whenexecuted by the one or more processors, further cause the one or moreprocessors to: determine at least one of a recommended amount of insulinor a recommended amount of carbohydrates for the patient; and presentthe at least one of a recommended amount of insulin or a recommendedamount of carbohydrates for the patient on a display of the device.